KELVIN MBEWE, Lusaka
ANIMAL, human and any other waste is simply unwanted and it is fit only for disposal.
At the most in Zambia, people use the substance as manure to enhance the growth of plants.
But there are some people who have seen waste as a resource which when processed, brings about useful properties such as lighting, cooking, and as a fuel.
The processing is known as biodigestion and it involves the fermenting of the waste products in a biodigester, which is a septic tank. The end product is a gas called bio.
Though on a small scale, the process was discovered a long time ago and some Zambians have adopted it.
This process is being encouraged world over because it’s sustainable owing to the fact that most of the resources used are free.
Lazarous Chewe is one of the few Zambians that can design and develop biodigesters and has built a number of them for different people.
He is a beneficiary of an exchange programme between Zambia and Japan which was sponsored by Government. Mr Chewe learnt the process in Japan and he has been practising it.
Biogas refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen. Biogas is primarily methane (CH) and carbon dioxide (CO2) and may have small amounts of hydrogen sulfide (H2S), moisture and siloxanes.
The gases methane, hydrogen, and carbon monoxide (CO) can be combusted or oxidised with oxygen.
“This energy release allows biogas to be used as a fuel; it can be used for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat,” he said.
Mr Chewe said the biogas digesters are common among pig farmers whom he designs for.
“Pig waste is solid manure and that is the type of material needed in a biogas digester. It is easy to collect,” he said.
He sees nothing wrong with the use of the gas to cook but added that Zambians take long to adopt new and innovative solutions.
With the variety of waste that can be used to produce biogas, owning a digester is not restricted to pig farmers but anyone interested in practising clean energy can have one.
At domestic level, fruit, food or kitchen waste, for a family on a plot size of about 70×70 can have a digester can act as the septic tank and a waste management system.
Mr Chewe said the end products in a biogas digester can also be used to nature plants.
Everyone hates smelly waste but his job is to remove the pungent smell and what remains is slurry, a substance that can be used as fertiliser.
For those with a green surrounding, the slurry would make it greener. Most people who go to Europe notice that the place looks extremely green and the reason is simple, they use slurry to nurture their surroundings.
And a pig farmer of Makeni, Limpo Phiri confirmed the usefulness of a biogas digester which has been installed at his farm.
Mr Phiri learnt about the technology in Kenya and Uganda. He came back home and fortunately for him, he came across someone who develops them in Lusaka.
“I went ahead and developed one and it has really helped me in keeping my chicks warm and lighting up my place,” he said.
To enhance the use of biogas, donors are pumping funds in biogas projects in the country.
Recently, the Swedish International Development Co-operation Agency (SIDA) gave the Netherlands Development Organization (SNV) US$ 4.7 million to implement the energy-for-agriculture (E4A) project in Zambia aimed at installation of biodigesters to enable rural households and smallholder farmers increased access to renewable energy.
The programme is meant to develop viable markets for biogas in Zambia that will lead to improved livelihoods for smallholder farmers through increased savings on fuel and income generation from the productive use of biogas and bio-slurry.
It will build capacity in the public and private sectors to construct and operate 3,375 bio digesters across the country by the end of 2018.
The initial work is intended to establish the capacity that will enable Zambia to continue to run a large-scale biogas programme even after the E4A project is completed.